Circuit for detecting an end point of an arc

(19)

(11)

EP 0 278 527 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	27.06.1990 Bulletin 1990/26

(43)	Date of publication A2:
	17.08.1988 Bulletin 1988/33

(21)	Application number: 88102203.2

(22)	Date of filing: 15.02.1988

(51)	International Patent Classification (IPC)⁴: G06F 15/72

(84)	Designated Contracting States:
	DE FR GB IT

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Priority:

13.02.1987 JP 31024/87

(71)	Applicant: NEC CORPORATION
	Tokyo (JP)

(72)	Inventor:
	Horiguchi, Ryuji Minato-ku Tokyo (JP)

(74)	Representative: Glawe, Delfs, Moll & Partner
	Patentanwälte Postfach 26 01 62 80058 München 80058 München (DE)

(56)

References cited: :

(54)	Circuit for detecting an end point of an arc

(57) A circuit for detecting an end point of an arc in XY coordinate system comprises a first register storing an X coordinate value of a given end point, a second register storing an Y coordinate value Yse of the same given end point, a third register storing a Y coordinate value Y of a coordinate point of a calculated arc pattern, a fourth register storing a Y coordinate Y of the same coordinate point of the same calculated arc pattern. A first comparator is coupled to the first register and the third register to generate a first coincidence signal when a content of the first register is coincident with a content of the third register and when a tangential angle of the calculated coordinate point is within a first angular extent. A second comparator is coupled to the second register and the fourth register to generate a second coincidence signal when a content of the second register is coincident with a content of the fourth register and when the tangential angle of the 4calculated coordinate point is within a second angular extent.

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